Mechanism for imparting rotary motion to index tables and the like



April 16, 1957 TO INDEX TABLES AND THE LIKE Filed Jan. 7, 1954 5 Sheets-Sheet 1 R. H. LISKA MECHANISM FOR IMPARTING ROTARY MOTION Mum.

. INVENTOR. RAYMOND H. LISKAI ATTORNEYS April 16,- 1957 R. H. LlSKA 2,

MECHANISM FOR IMPARTING ROTARY MOTION TO INDEX TABLES AND THE LIKE Filed Jan. 7, 1954 5 Sheets-SheetZ:

IN V EN TOR.

m u RAYMOND H. L/SKA k BY & Ma -4 (0 I A T TORNEYS 5 Shqets-Sheer. 3

TO INDEX TABLES AND THE LIKE INVENTOR..

. RAYMOND H. LISKA ATTORNEYS April'lfi, 1957 R. H. LISKA MECHANISM FOR IMPARTING ROTARY MOTION Filed Jan. 7, 1954 April 16, 1957 R. H. LISKA 2, ,6

MECHANISM FOR IMPARTING ROTARY MOTION TO INDEX TABLES AND THE LIKE Filed Jan. 7, 1954 5 Sheets-Sheet4 INVENTOR. RAYMOND H. LISKA tiapm W ATTORNEYS April 16, 1957 Filed Jan. 7. 1954 R.bt LEH A MECHANISM FGR IMPARTING ROTARY MOTION TO INDEX TABLES AND THE LIKE 5 Sheets-Sheet 5 HVVENTUR. IHGYWIOMMD IL LISUGd ATTORMHEYS United States Patent MECHANISM FOR'IMPARTING ROTARY MOTION TO 'INDEXTABLES AND THE LIKE Raymond H. Liska, Cleveland, Ohio, assignor to The Cleveland UniversallJig giompany, Cleveland, Ohio, a corporation of Ohio.

Application laiiuary 7,-1954, Serial N 402,743

6 C a ms 17 3) station to a maximum speed or velocity at a point mid-, way betweenthat stationand the nextstation, and back 7 to zero. speed or yelocityat the ,next station.

The present application isvdirected ,to a modification ofy themechanism described, in my aforesaid copending application, in which modification, certainbevel gears, bearings and other workingparts, have been eliminated,

thereby substantially reducing-thecost of manufacture ofthe mechanism,- without substantially; alteringthe nature of the movement obtained.

The .present invention also; has as one of its objects the provision of a mechanism of the character described which consists of a minimum number of parts that can be manufactured and assembled. at relatively low cost, which does not require frequentrepairor replacement of parts, but the parts of which are readily accessible for repair or, replacement, if necessary.-

Other objects and advantages of myinvention will be apparent during .the course of the following description.

In the accompanying drawings forming a part of this specification audin which like numerals are employed to designate like parts throughout thesame,

;Fig, 1 is;a top, planview of apparatus embodying the invention;

Fig. 2 isa front .elevational: view of the apparatus showninlFig, 1;

Fig. 3 is a fragmentary cross-sectional View, taken on the linev 3 30f Fig. 1;

Fig. 4 is a cross-sectional view, :taken on the line 4--4 of Fig. 2;

Fig. 5 is a cross-sectional view, taken on the line 5-5 portion} of the hou sing isa shaft 9, which is adapted,

to be rotated by ya worm wheelltl which surroundsthe shaft and has securedlt? oneendthereof (Fig.6) a

ri ig gear ll, haying internal ,teeth; 12. One; end of thegear 11 bears against one end of a member 13 which Such a mechanism imparts 2 3 contains the bearing 8, and ,whichis secured tothepor-h tion 2 of the housingbymeansof screws l lh Secured, to the member :13, as-by. screws ,15,, is a capor cover. member 16.. .Theworm wheel 10 iscontinuously-driven, by an electric motor 17 through the intermediary ofan endless beltv 18; a pulley 19, a shaft 20-and a worm, 21.

Splinetl or keyed to. theshaft 9 is a clutch ,,.member:22.., provided with gear teeth 23.;which are radaptedztobeai moved intodriving engagement withthe. ring gear. 11 at such timeswhenit is .desiredto drive the shaft 9.. .MQVfirmentyof theclutch member 22. for this purp ose may. be), effected in a number of ways, but in this instance, 1 use a clutch fork 24, whichis clamped to .a rod 25,..whichis mounted forreciprocal movementin the, housing-2 and; is provided. with a piston 26 atoneend which movesin: a cylindrical cavity 27 of the ;cap 16. .When the clutch... member 22 is to beengaged withthe. ring gear.,12,'compressed air isadmitted into the cylinder 27 through a conduit 28, causing the rod.25 to move to the left, as 1 viewed in Fig. 6. When the clutch member 22 isto be disengaged, compressed air is admitted into the cylinder, 27 through a conduit 29, causing,t he rod 25 to move to the right, as viewedin Fig. 6..-

The shaft 9 is provided at its inner end with a crank, arm 30, to which one end of a link or arm 31 is pivotally connected. This link aor arm 31 has journalled inian opening 32 thereof a drive gear, 33,. which is rigidly; se-.1- cured to the crank arm 30by means ,of screws 34. .The axis of the shaft 9 intersects thepitch circleof the, gear 33 and this -relationship-remains,constant; throughout the operation of the-device which will, be presently described.

The tdrivesgear 33FdIiV6S a second; gearn35 which is identical in size with the; gear-33 and lies in thewsame-i plane as the latter, being also free to rotate relatively to the link 31. For the purpose of permitting such, rotation,;1a pin 36, which extends axially through the gear 35 is rigidly secured to the link 31, as by means of a nut 37, and roller or pin bearings 38 and 39 are interposed between the gear 35 and the pin 36.

The link 31 is T-shaped, the arms31a and 31b of the link terminating in arcuate, end surfaces, 310 and 31d, respectively; The surfaces .310 and: 31d bear against wear plates .37,which are secured to the wall'of they, housing 2 by means of screws38., The arcuate surfaces. 31c. and 31d permit the link 31 to have a rocking or oscil-; latory movement in its own planeincidential, to the operation of the mechanism as will be; presently, described. The link is guided in such oscillatory; movement between surfaces40of the housingportion, 2 and surfaces 41-.of the spacer 4. I

Secured to the gear35, asbymeans of screws42 is a coupling element 43 which is inaxial alignment with the gear and is provided with a pair of spaced cars. 44 and 45which extend through an opening. 46 in a slideplate 47. which is interposed between thecoupling element 43 i and the covers of the housing. The cars 44 and 45 also extend through an oval-shapednopening 48 inthecover 5, which opening has a beveled edge; 49.

Journalled for rotation in the cars 44 and 45 is a shaft 50 having trunnions 51 extending at right, angles thereto, towhich the ears-52 and 53 of a second couplingmember 54'are pivoted. 1 Theparts 44, 45, 50,51, 52, 53 and 54 form a universal joint or coupling;

A shaft 55 extends from the coupling member-54, and

drives an index table through a universal it coupling 01' joint; 56 and shaft57.

The index table, designated: 58, f'iS mounted for rotation on a base 59. Rotation is effected by the-shaft-57w through the: intermediary of 1a bevel 1 pinion (not shown a beyel gear fl tl ig 3), and a shaft 261; securedltolthe center of the table 58.

The" table 58 is' provided at circumferentially-spaced pointswith recesses'tiZ-and- 63; in which are mounted bushings 64, which are adapted to receive the index pin 65, for the purpose of locking the table to the base 59. Th'e'recesses' 62 arid 63*define stationsof a two-station table, and in'thisca'se, are"180degreesapart. It will be readily understood; h'owever,that the tablemay be provide'd with anydesired number of such'recesses, defining additional station's.

'The indexpih may be a'ctuated'in any desired or conventio'n'al manner. In this case, the index pin is autom'atically moved into'lo'cking position by means of a compression coil spring, a'ndis retracted by means of compressed air'which enters*the"base-59' through a conduit 67, toex'ert pressure on the piston-likehead 68 of thepin 6 5.'-j

T he driving mechanisinwhich hasbeen described is desigaemmotate the index tablebetween stations, but in viwof 'the large mass which" is was thusmoved, it is desirable to impart tothe-table' a rotary motion which graduallyvaries from a-zerovelocity'or speed atone stasome a' maximum speed or velocity ata point midway between that station and thenext station, and back to zero speed er velocity atthenext station. It'is desirable, in other words, to produce'an intermittentrotary motion whic'h'willstart and stop the index table without shock and yet keep the table under 'positive'control throughout thecycle.

Such 'a' motion-has been'obtained by means of thedrive mechanism-shown and described in my copending applicatioii', Serial No. 369,942;

inthe present case, the motion is obtained through a modification of the mechanism described in that application, with the elimination of certain'parts of that mechanismwh'ich" is designed'to'reduce' costs to some extent, and utilize a more direct drive of the index table.

'The'gear ratiosin the present device are such that one complete 'revolution'of the shaft'9 will produce a half revolution of the index 'table 58, which iseq'uivalent to rotation'ofthe" table between its two stations.

The shaft 9 drives'the shaft 55 through the intermediary ofthe crank arm30, gear 33, gear 35, coupling element 43 and coupling element'54.

At the beginning of this rotation, the velocity of the gear 33 is zero,- and from this point until thecrank arm 30*has'" rotated through a half revolution, the velocity increases gradually, but relatively slowly, reaching a maximum when the crank armis at a position 180 degrees from that shown. From this point, and until the crank arm 30 hasreturne'd to its original or initial position, the

velocity changes'in the same manner, but is a decelerated velocity, becoming a zero velocity when the crank arm is in its initial I position a gain;

The movement may be understood-by reference to the explanation given in the aforesaid copending application; in the present case, however, a number of gears and other parts have been omitted; which considerably reduces the cost'of" manufacture of the drivingrnechanism.

Duringthe' movement of the gears 33 and 35, the end of the shaft 55 whichis "disposed in the coupling element 54rmoves'in an oval or elliptical orbit, which is'shown at "in Fig." 4,:this orbital movement being permitted by the universal couplin'g'of the shaft 55 to thecoupling member 43." The shaft 55 is'rnadc sufficiently long that the endofthe shaft which is-connected to the universal coupling 56*has virtuallyno orbital movement, the universal coupiingor joint 56 permitting the shaft 57 to rotate about its own axis only.

Thelinkfll, during-therotation of the shaft 9, moves in a path which causes the armssla'an'd 31b thereof to" slides =ov'erthe opening s, but at no time'uncovers thisopening. In this manner, the plate 47 provides protection against the entry ofdirtandforeigrr matter into the housing and mechanism.

in Figs. 2, 3, 4 and 6, means are shown, somewhat diagrammatically, for automatically retracting the index pin 65 at the beginning of the cycle of rotation of the shaft 9 and for automatically returning the index pin to locking position at the conclusion of this cycle.- Such;

means comprises a pin- 701 which proiects-fr'om' the end of the link 31, a pin 71 slidably mounted in the housing 1 switc 72;"

Referring to'Pigs; 3 and 6, it willb' ndte'd thatftliea'ir cylinder 27 is provided with two conduits 28 and 29j-conduit 28 in Pig: 6 being a continuation of-this-ccnduit shown in Fig. 3. An air vent is shown at 73 (Fig. 3), and a pull red at 74. Conduit 67 (Fig; 3') and'c onduit 29 (Fig. 6) are connected to a four-way electrically-operated air valve (not shown), normally deenergized, so as to admit compressed air through-conduit 2) (Fig.6) into'the chamber at the left of the piston-'26, thereby keeping clutchmem was disengaged and letting air escape through'conduit as (Fig.- 3) and through said air valve.

position shown; a

In order to start an indexing c'ycle, an electricmanuallyoperated push button not shown) will energize' the aforesaid electric four-way valve, thereby reversing the compressed airflow. Air will now new throughc onduit 67 (Fig. 3) into the upper chamber of the index pin cylinder;

thereby disengagingindex pin 65; When-the index pin is safely disengaged the upper surfaceof' piston 63 will uncover the air port to'which conduit'28is attached and carry compressed'air through conduit 28 into the chainber at the right of the piston 26 (Fig. 6), forcin'g piston to the left, thereby engaging-clutch teeth i2 and23'. Since the worm wheel it is in constant motion, the index cycle is started and continues until pin 70 again'camspast pin "it which, through switch 72, deenergizes the four-way' valve, reversing the compressed air fiow,*disengaging the' This completes clutch teeth, and engaging the-index pin. the index cycle, during which gear 35 will have revolved one revolution, from zero to-zero motion.

The aforesaid method of operation provides anihter-' lock feature which at no time-permits 'simultaneousem gagement of the index pin and drive clutch'whichmigh't cause breakage of parts.

The pull rod 74 is provided for the purpose of'manually disengaging the index-pin during job set-up or checking.

it is to be understood that the form of my invention,-

herewith shown and described, is to'be takenas a'preferred example of thesarne, and that various changes-in" the shape, size, and arrangement ofpartsmayberesor'ted to, without departing from the spirit ofmyinvention, or the scope of the subjoined claims.

Having thusdescribed my inventioml claim:

l. in a mechanism for rotating an index table in-a pr'e-' 1 determined pattern of speed, a drive shaft'having a'cran'k arm, a gear rigidly secured to said crank arm and having 2. Mechanism, as recited in claim 1, in which the axis of the drive shaft intersects" the pitch circle of 'the'firstnamed gear.

3. Mechanism, as recited in claim 2, including elements secured to said second gear constituting a universal joint, and a second shaft driven by said universal joint.

4. In mechanism of the character described, a housing,

having-an elliptical-shaped opening, a Cover plate eoven This permits" spring 66 (Fig. 3) to keep the index pin in the locking ing said opening at all times, and means for constraining said cover plate to move in an elliptical path, said means comprising a shaft, a crank arm on said shaft, a gear fixed to said crank arm, for rotation therewith, a link, having one end thereof pivotally secured to said crank arm c0- axially with said gear, means defining a rectilinear path of movement for the other end of said link, and means connecting said cover plate to said link intermediate the ends thereof.

5. Mechanism, as defined in claim 4, including a second gear rotatably secured to said link intermediate the ends thereof, and in mesh with said first gear, whereby said second gear is movable by said link in an elliptical path.

6. Mechanism as defined in claim 5, wherein said lastnamed means comprises a driven shaft traversing said cover plate and secured to said second gear for movement therewith.

References Cited in the file of this patent UNITED STATES PATENTS 

